High-strength carbon nanotube/carbon composite fibers via chemical vapor infiltration

Abstract

In this study, we have developed an efficient and scalable method for improving the mechanical properties of carbon nanotube (CNT) fibers. The mechanical properties of as-synthesized CNT fibers are primarily limited by their porous structures and the weak bonding between adjacent CNTs. These result in inefficient load transfer, leading to low tensile strength and modulus. In order to overcome these limitations, we have adopted chemical vapor infiltration (CVI) to efficiently fill the internal voids of the CNT fibers with carbon species which are thermally decomposed from gas phase hydrocarbon. Through the optimization of the processing time, temperature, and gas flow velocity, we have confirmed that carbon species formed by the thermal decomposition of acetylene (CH) gas successfully infiltrated into porous CNT fibers and densified them at relatively low temperatures (650-750 °C). As a result, after CVI processing of the as-synthesized CNT fibers under optimum conditions, the tensile strength and modulus increased from 0.6 GPa to 1.7 GPa and from 25 GPa to 127 GPa, respectively. The CVI technique, combined with the direct spinning of CNT fibers, can open up a route to the fast and scalable fabrication of high performance CNT/C composite fibers. In addition, the CVI technique is a platform technology that can be easily adapted into other nano-carbon based yarn-like fibers such as graphene fibers.

Biomass‐Derived 3D Carbon Aerogel with Carbon Shell‐Confined Binary Metallic Nanoparticles in CNTs as an Efficient Electrocatalyst for Microfluidic Direct Ethylene Glycol Fuel Cells

“…During the catalytic conversion of Pd 100 and Pd 52 –Ni 48 nanoparticles, respectively, in to Pd 100 /CNT and Pd 52 –Ni 48 /CNT on carbon fibers, the precipitation of carbon atoms heals the damage created by the nanoparticles via the linkage of the defected perimeters of the graphitic layers . Furthermore, the escalation of CNTs on carbon fibers mechanically reinforces the CAs, which promotes the load transfer efficiency via the enhanced physical entanglements on the surface of carbon fibers . In specific, the higher catalytic activity and stability of Pd 52 –Ni 48 bimetallic nanoparticles facilitate uniform CNT growth with enhanced interface interaction on carbon fibers, demonstrating considerable flexibility of Pd 52 –Ni 48 /NSCNT/CA (Table S2, Supporting Information) than that of Pd 100 /NSCNT/CA and elucidating its application in stretchable electronic devices.…”

An Overview of the Recent Progress in the Synthesis and Applications of Carbon Nanotubes

“…Now, scientists are capable of the enormously enhanced integration density of the device, thus attaining enhanced speed and efficiency with promising applications in energy saving and integrated circuits. It is understood that CNT-electronics share the potential, together with biotechnology, for the advancement of current devices [3]. Some of their applications are given below.…”

“…The nanosized carbons (or nanocarbons) comprise fullerenes, graphene and CNT [2]. Extraordinary importance is given to graphene and CNTs, as they play a vital role in current advances based on nanomaterials, including conductive and high-strength composites [3], artificial implants [4], drug delivery systems [5], sensors [6], energy conversion and storage devices [7], radiation sources [8] and field emission displays [9], hydrogen storage media [10] and nanometer-sized semiconductor devices [11], probes [12], and interconnects [13]. Radushkevish and Lukyanovich first detected and described CNTs in 1952 [14], and later, the SWCNTs were observed by Oberin in 1976 [15].…”

Direct spinning and densification method for high-performance carbon nanotube fibers

“…As different approaches to synthesize high-performance CNTFs, various post-treatments have been performed on CNTFs that had been synthesized by the direct spinning method in which CNTFs are directly drawn from CNT aerogels formed in the CVD reactor. These treatments include the induction of chemical molecular crosslinking between CNTs 7,8 ; liquid infiltration and subsequent densification 9–12 ; polymer infiltration and sometimes subsequent carbonization 13 ; mechanical densification 14,15 ; and vapor phase carbon infiltration 16 . Most of the techniques successfully increase the mechanical or electrical properties, or both, of as-synthesized CNTFs, but in many cases these post-treatments require significant processing time to achieve meaningful improvement of CNTF properties.…”